Power-operated gbaijst-dook



Oct. 22, 1929. BREEST ET AL 1,732,217

POWER OPERATED GRAIN DOOR TABLE Filed Sept. 29, 1926 INVENTORS fiwa/s EEEST' UNi'l'hD SKATES earner orrrcs POVIEB-OPERATED GRAEN-DOOR TABLE Application filed September 29, 1926.

Our invention is of a power operated grain door table.

The invention will be best understood from the following description of certain forms of apparatus embodying the invention shown in the accompanying drawings, in which Fig. 1 is a perspective view of a power operated grain door table making use of fluid pressure for power operation. Fig. 2 is a detail view of a toot operated switch for the apparatus of Fig. 1. Fig. 3 is a detail of a modified construction making use of electrical control.

The table 10 may be constructed as desired to embody the stationary abutment bar 12 and the movable compressor bar 14;, between which the boards are tightly held while a batten or the like is being nailed, the steel plate 16, with which the table is covered, serving to clinch the nails as they are driven. Table 10 is preferably provided with a shelf 19, upon which the power operating devices may be supported.

in the form shown in Figs. 1 and 2, such power operating devices comprise the fluid pressure cylinders 20, 20 containing pistons which transmit pressure to the movable bar 14; through the levers 22, 22, these parts being retracted, when the pressure is ofii, by retraction springs 24 2d. l Vhile a short connecting rod may be used if desired, a pin and slot connection as shown at 25, Fig. 1, is ordinarily suiiicient.

The power applying fluid such as water, steam, compressed air or the like, is preterably controlled by valve means operated by the foot of the nailer or nailers. In the form shown in l i 1. and 2 the valve 26' controls communication from fluid pressure supply pipe 28 to the cylinder teed pipe 30, and the outlet from cylinder 20 and pipe 30 is through the valve 32. The pivoted rocker member 34 is normally held by spring 36 in position to close valve and open valve 32, but when tur ed by pressure applied to treadle 38, the exhaust valve 32 is closed and supply valve 26 opened, and the resulting advance oi the piston in cylinder 20 produces the required clamping action oi the corresponding end of the compressor bar 14.

fine oi? the control mechanisms, such as Serial No. 138,498.

shown in 2, is provided for each cylinder at opposite ends of the table, and when the treadles are unconnected one may by operated by each nailer, but the treadles 38 may be connected by a master bar 40 so that both may be operated together, if desired.

with the power operated table, the lumber can be clamped with substantially any desired clamping pressure and a tighter, better door produced, and the device being readily and simply operated and requiring no exerti on of strength by the nailer makes it possible to secure increased production as compared with former devices and the men still be in better physical condition after the days work.

In 8 we have shown the substitution of solenoids 4-2 for the fluid pressure cylinder 20, making it possible to use electrical power instead of power supplied by fluid pressure. A toot operated switch 41 is conveniently located to enable the operator to depress a button 43 which closes the electrical circuits for the corresponding solenoids 42, 42 by means of switch 44, thus energizing the solenoids 4:2 and compressing the lumber by the compressor bar 14. l Vhen the pressure on the button 4-3 is released the switch 44 is opened and the compressor bar 14 and connected parts retracted by the springs 24, leaving the table free for the removal of the completed door or other product and the insertion of new lumber for the subsequent operation. Both solenoids may be connected up with a single switch, or separate switches may be used "for each solenoid, as desired.

The constructions shown are intended for purposes of illustration only, and not for limitation oi"- the invention, the scope of the invention being as defined by our claim, by which we desire to include all that is new over the prior art.

Vi e claim:

A power operated work clamping table havi. a fixed abutment and a movable work clamping member, levers connected to the clamping member in the neighborhood of its opposite ends, a shelf beneath the table, a fluid pressure cylinder and its piston on such shelf in the neighborhood of its opposite ends, said pistons being arranged to operate said respective levers, a fluid supply pipe for each cylinder, inlet and exhaust valves for each cylinder, a pair of rocker members arranged to actuate said valves, a treadle arranged to actuate each of said rocker members, and a master bar extending between said treadles. In testimony that We claim the foregoing, We have signed our names hereto.

FRANCIS BREEST. OTTO 'HERVIG. 

